Coal burner and feed mechanism



Aug. 15, 1933. s. KLEIN 1,922,960

COAL BURNER AND FEED MECHANISM Original i e g- 1927 2 Sheets-Sheet l INVENTOR \S CZa 1d flce ATTORNEY Aug. 15, 1933. KLE|N COAL BURNER AND FEED MECHANISM 2 Sheets-Sheet 2 Original Filed Aug. 16, 1927 lilllllllll INVEN'I UR Patented Aug. 15, 1933 UNITED. STATES 1,922,960 COAL BURNER AND FEED MECHANISM Silard Klein, New York, N. Y.

Application August 16,

1927, Serial No. 213,235

Renewed January 6, 1933 8 Claims.

My invention relates to a fire-box or coal burner and feed mechanism therefor, which are especially designed for the efiicient use of fine coal, such, for example, as the grade usually called buckwheat.

The general object is to secure improved and highly efficient combustion, and provide at the same time improved and efiective means for feeding fuel, supplying air and removing ash.

Other objects are, to provide a reasonably simple fire-box or furnace structure in which the coal bed is disposed in general annular arrangement about a central space or chamber, and combustion occurs in a relatively shallow upper layer of the coal bed which is maintained in inward and downward sloping form whereby the ash moves by gravity into the central chamber; to efliciently supply air for combustion immediately below the combustion zone and from opposite sides of the annular combustion area; to supply additional air above the coal bed for effective combustion of gases; to preheat the air; to provide effective means for feeding coal substantially to the center of the annular coal bed and forcing it upward about the central chamber; to supply air under pressure, and to control the coal and air supplies arbitrarily or automatically and further to properly regulate the rate of coal feed in relation to the rate of air supply under different operative conditions; and to provide convenient and effective means for removing ash from the central chamber.

The characteristics and advantages of the invention are further sufficiently explained in connection with the following detail description of the accompanying drawings, which show an exemplifying embodiment. After considering this example, skilled persons will understand that many variations may be made within the principles of the invention, and I contemplate the employment of any structures that are properly within the scope of the appended claims.

Fig. 1 is a central vertical sectional view of a structure embodying the invention in one form.

Fig. 2 is a section at 2-2, Fig. 1.

Fig. 3 is a detail sectional elevation on line 3-3,

Fig. 1.

. fire boxes.

Fig. 4 is a section at 4-4, Fig. 1.

Fig. 5 is a section at 5-5, Fig. 4.

The invention may be incorporated in or applied to various types of furnaces, and the burner structure may be adapted to various shapes of In the present example the invention is incorporated in a furnace of generally cylindrical form, including the base chamber or casting 1 which constitutes the ash box of an ordinary furnace, a cylindrical casting 2 corresponding generally to the fire-box of an ordinary furnace, and an upper structure 3 which may contain any suitable structure to be heated, such as air jackets, water or fire tubes. In the intermediate casting or fire-box 2 is a dished partition 4 conveniently identified as a fuel support or receiver. This may be of generally hemi-spherical form. Centrally located above and within the fuel support isa composite structure 5 identified for convenience as a central housing, theouter portion of which serves as the inner form or guide for the fuel body, and which also provides for feeding air, and receiving and discharging ash. This housing may be in one piece. Specifically as shown it comprises a generally hemi-spherical bottom 6, spaced above the bottom of the fuel support 4 by legs 6a. Upon the bottom 6 is an intermediate section 7 consisting of an inner wall 8 and outer wall 9, secured in spaced relation by vertical webs 10. Secured on section 7 is a top burner section 11. The sections 7 and 11 are formed to providein effect a continuous'upward- 1y diverging conical wall 12. The top section has a horizontal, fiat, annular top face 13, and leading therefrom an upwardly flaring inward conical face 14; and below that face or surface a cylindrical inner surface 15 aligned with the inner surface of wall 8 of the central housing section. The inner face of the fuel support 4 and the outer face of the central housing define a fuel chamber 16 of generally annular, bowl-shape. Fuel is forced into the bottom of this chamber in a manner to be described, and because of its fine or granular form readily flows upward to fill the fuel chamber and assumes at its upper surface a conical formation as at 17, the location and slope of this fuel cone being the angle of rest of the loose material, asdetermined by the inner edge of the annular top face 13 of the central hous- The furnace sections 1 and 2 fit closely together at the joint 18, to provide an air tight chamber 19, which comprises the entire lower part of the furnace below the fuel support 4. Air is supplied to the chamber under suitable pressure by means to be described, and is fed therefrom to the fuel body at different points or at different zones. Thus the fuel support 4 has at its upper edge an annular fitting 20, the upper edge of which is in tight contact with the inner face of the fire-box 2, and in this fitting is a series of spaced air ports or jets 21 through which air is supplied from chamber 19 to the outer portion of the fuel body and passes upward therethrough. The top section 11 of the central housing is also provided with one or more series of outwardly directed, spaced air ports or nozzles; specifically as shown, there is an upper series of spaced air ports 22, and a similarly spaced lower series of air ports 23, discharging approximately horizontally into the fuel body at points somewhat below the combustion zone 24, the upper portion of which is at or near the conical surface 17, and the lower portion is and 42 projecting from the inner walls of thev approximately defined by dotted lines 25. Desirably also a series of 'annularly spaced ports or jets 26 is provided in the inward conical face 14. Air'is supplied to all of the ports 22, 23, and 26 through a passage 27, connecting the bottom wall 6 of the central housing and wall 4 of the fuel support, and thus affording communication between the air chamber 19 and the hollow wall structure of the central housing. As illustrated, said air ports 22, 23 and 26 preferably have reduced cross sections as'compared with the supply passage 27 and the indicated intermediate air passages, for the purpose of increasing the relative speed of discharge of the air through said air ports. This passage 27 has such diameter and is so formed that fuel readily fiows around it.

For the continuous or intermittent supply of fuel to the fuel chamber, a vertical fuel tube 30 is connected to the bottom of the fuel support 4,

the lower end of this tube being closed and supported by a base 31. A horizontal fuel tube 32 is connected to the lower portion of tube 30, and

extends to the exterior of the furnace at one side usual furnace door is removed and a special door or closure 33 is applied and secured to the door frame 34, this closure providing for suflicient airtightness of the air chamber 19 and also for the proper location and support of the horizontal fuel tube 32, ash discharge pipe, air supply tube and other items to be described. A shaft 35 extends through the vertical fuel tube 30 and through the center of the central housing, and is provided with bearings at 36, 37 and 38. On this shaft is a fuel feed worm 39 of the same length as the vertical fuel tube. At its upper end the shaft also has spaced radial lugs 40 cooperating with upper and lower spaced lugs 41 central housing; these lugs serve as clinker breakers. The interior of the central housing constitutes an ash pit or chamber 75, and therein shaft 35 is provided with an ash feed worm 43.

A coal hopper is connected at its lower end to the outer. end of fuel tube 32. A shaft 51 passes through the lower end of the hopper and centrally through tube 32 and is supported in bearings at 52 and 53, the bearing 53 being supported by a spider so that fuel may pass from tube 32 into tube 30. Any suitable fuel-feeding means isprovided on shaft 51, such as the spaced angular blades 55, which serve to properly advance the fuel without undue friction.

Shaft 35 is driven by bevel gears and a shaft 61, having a bearing 62 in support 31 and passing out through cover plate 33. The outer ends of shafts 51 and 61 may be connected by gears 63, 64to turn at the same or different speeds, the coal impelling devices 39 and 55, and the ash impeller 43 being designed to move the respective materials'at the proper rates, with relation to shaft speeds.

Air is supplied to chamber '19 under suitable pressure by a blower 70 and air pipe 71 passing through the cover plate 33.

Ash discharged from the lower end of chamber 75 in the central housing, passes into a downwardly inclined conduit 76, which extends through a lower portion of the coal chamber, and a con nected pipe or conduit '77 carries the ash to aconvenient point of disposal.- Desirably mechanical means is provided for conveying the ash to a dump, or into cans. Thus conduit 77 is connected to a downwardly inclined chute 78, and this connects to an upwardly inclined conduit 79 having a discharge spout 80, located in an ash-can 81. A screw conveyor 82 is revolubly mounted in conduit 79, and its shaft 83 is driven by worm gearing 84 from shaft 61.

A motor 90, see Fig. 4, may be direct-connected to the blower-shaft 91 at one side of the blower casing, and the blower shaft 91 extends to the opposite side of the blower casing, and is provided with a worm 92, engaging a worm gear 93 on a shaft 94, which is a part of any suitable change-speed gearing for varying the relative rates of coal-feed and air supply. For this purpose the gearing also includes stepped gears 95, 96, 97, fixed on shaft 94, and shiftable gears 98, 99,100 splined on shaft 61, from which the coal and ash-feeding devices are driven.

The driving means or connections may be varied greatly for different purposes.

Any suitable fuel such as coal of the finer sizes (buckwheat or dust, for example) is advanced from the bottom of the hopper 50 through tube 32 by the propellers 55. Reaching the bottom of the tube 30 it is forced upward by the helical conveyer 39, and enters the coal chamber at the bottom thereof, and flows upward, passing around the air passage 27 and ash pipe 76, until it reaches the level 17, and is maintained substantially at that level by continuous or intermittent operation of the feeding devices. Air is at the same time supplied under pressure to chamber 19, and passes into the fuel body near the outer portion thereof through the ports 21 and also into the inner portion of the fuel body, close to the combustion zone, through the ports 22 and 23. Thus an ample supply of air is provided to the entire combustion zone to promote the most elficient combustion of the fuel, and it will be noted that combustion takes place only at and near the surface of the coal body so that undesirable conditions encountered in the average furnace are entirely avoided. In the present burner, fresh fuel is always supplied from below, this fresh fuel-elevating the burning fuel and maintaining it always in the desired combustion zone; that is, at the top of the fuel bed. The fresh fuel is in this way only gradually heated and its gases are not prematurely driven off but are gradually distilled, some of the gases. being extracted before the coal actually comes intothe combustion zone; but a large part remaining and being driven off during actual combustion in the zone of burning. Air is also supplied through the ports 26 to the conical area within and above the coal combustion zone, thus furnishing an ample supply for the complete combustion of gases. The air supply is also preheated, either by'passing through a. considerable portion of the heated coal body, as in the case of air passing through ports 21, or in contact with heated metal walls of the central housing, in the case of air going through ports 22, 23, and 26.

As ash forms on the upper surface of the combustion zone it falls by gravity down the conical surface of burning coals and down the conical surface 14 of the central housing and into the chamber 75 therein and then descends by gravity a certain amount of clinker will be formed, and

the revolving lugs 40 moving between the stationary lugs 41 and 42 provide for breaking up such clinkers into relatively small fragments so that they will freely pass downward, and also to prevent the clinkers from impeding the ash movement. The worm 43 also serves to positively force the ash through the lower ash passages.

Any known or suitable automatic controlling device may be provided, such for example as a thermostat subjected to temperature of steam or water heated by the burner and arranged to make and break the circuit of the motor 90. Or in some cases where the burner is used to produce steam under pressure, an automatic pressure control may be provided for the same purpose. Such appliances are well known and therefore not shown or particularly described. The changeable gearing shown in Fig. 5 permits the rate of fuel feed, in relation to air feed, to be properly adjusted for different operating conditions; but such variable control may be omitted or other controlling arrangements may be provided as may be necessary in particular cases.

I claim:

1. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a bottom opening, means for supplying fuel through said bottom opening and means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure.

2. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a curved bottom provided with an opening, means for supplying fuel through said bottom opening, means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure, and means for removing ash from said substantially central opening.

3. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a curved bottom provided with an opening, means for supplying fuel through said bottom opening, means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure, clinker breaking means disposed in said substantially central opening, and means for removing ash from said substantially central opening.

4. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a bottom opening, means for supplying fuel through said bottom opening, means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure, said air supplying means including a com partment surrounding the bottom of said annular structure, clinker breaking means disposed in said substantially central opening, and means for removing ash from said substantially central opening.

5. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a curved bottom provided with an opening, means for supplying fuel through said bottom opening, means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure, rotary clinker breaking means disposed in said substantially central opening, and means for removing ash from said substantially central opening.

6. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a bottom opening, means for supplying fuel through said bottom opening, means communicating with the interior of said certain hollow walls to supply air through said perforations into the bed of fuel within said annular structure; said air supplying means including a compartment surrounding the bottom of said annular structure, clinker breaking means disposed in said substantially central opening and proximate its top, and means for removing ash from said substantially central opening.

'7. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continu-' ously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a curved bottom provided with a central opening and with a non-central opening, means for supplying fuel through said central bottom opening, means communicating with the interior of said certain hollow walls through said non-central bottom opening to supply air through said perforations into the bed of fuel within said annular structure, and means for removing ash from said substantially central opening.

8. A burner of the class described comprising a substantially annular structure, certain of the walls of which are hollow and extend continuously about a substantially central opening, the outer walls of said certain hollow walls being provided with perforations, said annular structure having a curved bottom provided with a central SILARD KLEIN. 

